The present invention concerns a plug-in connection for connecting a plug-in part, especially one formed by one end of a pipe line, which consists of a receiving housing with a plug-in opening for the plug-in part, a circumferential seal for sealing a circular gap between the receiving housing and the inserted plug-in part as well as valve element, which when it is disconnected, closes automatically in order to provide run-out protection for the housing, and which valve element can be opened by means of inserting the plug-in part.
Such a plug-in connection is known from the EP 0 702 187 A1. This known "quick connect unit" represents a costly design because, on the one hand, the circumferential seal, which is provided for sealing the inserted plug-in part consists of two individual sealing rings, and on the other hand, the valve element is guided in a guide sleeve, which is sealed against the receiving housing by a first seal. The valve element itself, when it is in its closing position, can be sealed by means of a second seal against the guide bushing.
The DE 42 14 104 A1 describes a "leak-free plug-in connection", which consists of one coupling part and one plug-in part, which can be inserted into it. In each of them, in the connection part as well as in the plug-in part, one check valve is included. Each check valve has its own seal in order to seal it against the housing in the closed position, and the plug-in part is sealed by means of a separate circumferential seal against the connection part.
The present invention is based on the task of creating a plug-in connection of the generic type described at the beginning, which--due to its especially simple design configuration--is favorable with regard to cost.
In accordance to the invention, this is achieved in that the valve element, in order to close the receiving housing, acts directly together with the same circumferential seal, which is actually associated with the plug-in part. This means, that the circumferential seal--preferably formed by a single sealing ring--when the plug-in part is disconnected, is located directly in the circular gap between the receiving housing and the valve element, and when it is disconnected, it is located directly between the receiving housing and the plug-in part. As far as the design is concerned, this is accomplished in that the valve element includes a sealing region, which acts jointly with the circumferential seal, which sealing region, as far as its exterior circumferential contour is concerned, corresponds basically to the plug-in part. When the plug-in part is now inserted it can thus be guided through the circumferential seal, which causes the valve element to be moved at the same time away from this (only) circumferential seal.
According to the invention there is thus only a single circumferential seal still required, in order to, on the one hand, to ensure sealing between the inserted plug-in part and the receiving housing, and on the other hand, however, also sealing of the valve element in order to ensure run-out protection when it is disconnected. From this a very simple--and therefore advantageous regarding its price--construction method results.
Further advantageous design characteristics of the invention are shown in the following dependent claims as well as in the following description.